Distance finder



A.l F. NEcToux July 6 1926.

DI STANGE FINDER Filed Nov. 29. 1924 3 Sheets-.Sheet 1 A. F. NECTOUX DISTANCE FINDER Filed Nov.k '29,

3 Sheets-Sheet 2 ire enfuir @afan/X July 6 1926. t 1,591,877

A. F. NEcToUx DisTANCE FINDER Filed Nov. 29. 1924 I5 Sheets-Sheet 5 Luenfr:

Patented July 6, 1826.

hitl?? :E FIC E ANDR FBANQOIS NECTGUX, OF PARIS, FRANSE, ASSIGNOR T0 SOCIT DES LUNETERS, OF SAES. IFR-ANGE, A CORPGRATON. l

nrsrancn Finnen.

Application led November 29, 1824, Serial No.y 753,602, and. in 'France December 14, 1923.

The present invention relates to an instru-a ment having for its object to determine with reference. kto the observation point the polar co-ordinatesot a succession ot points upon the ground to be surveyed, as well as the altitude of each point.

The instrument according to the invention, which may be iurtheremployed as a plane table, also serves to lay out the plan of the said ground.

In order to ascertain the distance of a given point with the said instrument, each operation comprises the use of two similar right-angled triangles having a common ver tex located at the observation point. For one ot the triangles, the verter: ot the right angle is located at the point to be determined, and for the other, in the line of sight and at a short distance from the observation point; the sides, which do not pass through this point, have in each case a predetermined length. Y l

The said theoretical system of triangles is utilized inthe improved instrument by pr viding two cooperating rulers whereof one is'directed upon the point to be determined and the other upon the end oi the third side of the first triangle, this sidebeing formed by a perpendicular line of stat-ed length which is drawn from the said point to the line formed by the polar radius oi' the. latter.

The second side of the right angle of the second triangle is constituted by an yedge of known length of a biock which is slidable upon the iirst mentioned ruler.

rlhe said instrument is completed by suitable sighting glasses, graduated circles and spirit levels whereby accurate measurements may be obtained, and the relative position of the point to be observed' can be plotted in a very enact manner by means ot a vertical pin which is situated at the vertex of the right angle of the smaller triangle and is brought ydown so as to puncture a suitable Vpiece of oil cloth which is stretched upon the instrument board.

After obtaining the distance. of the said point, its altitude can be found by the use of a vertical scale placed in line with the said pin, thus odering a practicalrealization ot the two like triangles situated in the same vertical plane.

lt is thus noted that the said instrument, which is handled with great facility, can be employed by operators having but a moderate skill, so that a saving in the cost of operating will be afforded, and this is furthered by the fact that the calculations, which always require a considerable time in the Yordinary topographical methods, are now eliminated.

The appended drawings drawings which are given by way of example show a practical embodiment of the said invention.

Fig. l is a diagram illustrating` the method employed in the apparatus for the measurement of distances.

Fig. 2 is a diagramof like nature showing the method of measuring the differences of level.

F ig. 3 relates to apparatus used for erecting upon the observed point a line ot stated length perpendicular to the polar radii of the said point.

l Fig. 4L is a vertical cross section of the improved surveying instrument.

Fig. 5 shows a detail ot the same.

Fig. 6 is a plan view of said instrument'.

F ig. 7 is a detail View of the slide.

Referring to Fig. l, it is observed that in the method employed for measuring the dis tance from a point A to a point B, two similar right-handed triangles A B C and A b c are drawn; the sides B C and b c have a con-` stant length. The ratio sans Ab bc offered by the two triangles allows of calculating A B, since A can be readily measured.

In Fig. 2 it is observed that the method tor determining the. difference of level between the point at which the instrument is placed and the point under observation is analogous to the above described method 'for distance finding. y

According` to this method two similar triangles A B D and A CZ are laid out which are situated in a common vertical plane; these triangles will immediately aEOrd the ratio BD AD bd Ad in which A D is known and l) d and A d can be readily measured.

Fig. 3 shows thev instruments used upon the ground i'or marking out the line perpendicular to the. radius A B starting from the point B -and for limiting` this perpendicular to a constant and speciiied length. One ot the said instruments is an optical square mounted upon the tripod support 1, and comprisingl a spirit level and a rig t-angled telescope 2, upon which latter is mounted a collimator 3 making a 90o angle with the line ot sight oi the said telescope. A; stake e is normally used with the telescope; it is sunk into the ground at the point to be determined, and the telescope is placed above the saine so that the colliinator shall be situated in the vertical axis.

A secondary device employed for determining the line A B is a leveling rod 5 coinprising a. slide vane 6 which is vsecured vto an attaching piece 'l' provided with a dynan'io'ineter spring S to which is attached one end ot a steel tape 9 oi a given length (usually 2O metres) which is connected at the other end to the top ot the stake Jl. 'lhc vertical distance between the collimator and this end of the tape. should be equal to the distance between the slide vane (l and the attaching point 7, so that the line ot sight of the collimator will be -perallel to the line connee ving the top olE the stake to the attaching point i".

The instrument according to the invention is adapted for use at the observation point. It comprises essentially a ciri'rular board 10 which is mounted at the top 'of a support and has disposed thereon various measuring devices. l

The sheet ot paper or oil cloth upon which the'points are plotted is stretched upon and attached to the said board by suitable. means, known Aper se` Three bearingsI 12 projecting below the said board and rigidlyv connected therewith are adapted to rest respectively upon the pointed ends of three screws 1B which are suitablyv mounted in the head 1l ot the support 15. The said board and the head 1e are connected together b v mez is ot' a pivot axle 16 which is provided with a shoulder fitting accurately in a recess 1formed at the centre of the said board. said axle ending at the bottom in a milled head 11 supporting the spring 18 which abuts at the other end below the head 1l traversed by the said axle.

The six branches of the sai-d support (se Fig. 5), which are disposed in pairs, are pressed against the head lei by means ofi the wedges 19; each wedge is urged outwardly bv the spring 70 and is controlled bv a r :LLLW Q0 cooperatingwith a nut 71 secured to the said head. The whole 'device i'or securing the branches as above arranged will thus require the use oi three wedgeseach of which serves for two adjacent branches not forniing part of the same set.

Upon the upper end of the axle 1G is mounted the bearing 21 upon which are pivoted the ruler 22 situated upon a diameter and a radial ruler 2i. At the central part of the diametral ruler 22 is a support upon which is mounted the telescope Q0 oi the optical square type having thereon a spirit level i7 and adapted to be rocked about a horizontal axle 28 by means ot' a pinion 20 engaging a toothed Sector 30. A sighting device 31 situated in line with the a. e l0 is disposed above the said telescope and may be adjusted in position by means of a pinion 32 acting through the nied'iun'i o'l' the rack 33 upon the tube 72 carrying the lens lil.

Upon the support is mounted a second telescope or sighting glass Si 'for obserng the graduated scale 35 disposed in a circular recess surrounding the axle 16 and adapted to be closed by a suitable cover. One branch of the ruler is accurateljv tinished upon one ot its `laces which passes through the centre of the board and is suitably graduated. The slide i6 is movable along the latter branch; and it has termed therein an opening t? with a suitable scale serving as a vcrnier and is provided with a block lS having an edge oi determined length which is perpendicular to the said radial 'tace of the ruler 22. At the vertex of the rightangle thus formed is verticallyv disposed a socket di) having movable therein against a spring (not shown) a plunger which provided with a stop or stud 51 and carries at the bottom the lpointer Upon the sait slide is also mounted a graduated scale 53 situated on the saine vertical line as the pointer 52; it may 'be folded down when not in use, a set screw l5 being provided to retain it in adjusted position. A spirit level 54 is also mounted upon the said slide.

The second branch of the ruler 22 is provided with a compass 55; its end is supported by the outer edge 38 oft' the board l0 through the medium of a. block 42 which is attached to the said ruler b v means ot the screw 43 which is suitably engaged in the slot Li-l. A tongue 30 which is capable of pivoting with respect to the said block under the control of the screw l0 is adapted to press against the said edge and to tighten the whole device. A horizontal screw l5 mounted in the said ruler and a stud l0 pressing against the latter by means ot' the spring sti" are also disposed at either side of the bloc r for the accurate adjustment of the said ruler.

rl`he radial ruler 2e is secured to a support 56 analogous to the support Q5, and is pro` vided like the latter with a sighting glass 5.7 of the same type as the ill- The ruler Qd may be maintained against the outer edge 3S of the board 10 by means oi' a device analogous to the one above dcYs-cribed but comprising onlyr the tongue oi controlled by the screw 36. A slotted arm 5S is adapted to engage the screw 59 which traverses the end ot the straight branch of the diametral ruler 22, thereby connecting the latter to the ruler 24 which has also an accurately As above mentioned, the said instrument serves for direct readings or as a plane table, and in the latter case, a sheet of paper or preferably a piece of oil cloth is stretched upon the board 10 which latter is provided for the purpose with a central aperture for the insertion of the axle 16.

The operation is as follows:

The apparatus is set in direction by the use of the compass 55; during this time the operators assistants make use of the telescope and the slide 6 to draw from the point B whose distance is to ,be-measured, and upon the polar radius of said point, an imaginary perpendicular line B C of determined length; for this purpose they sight with the glass 2 upon the disc 3l of the instrument, and with the collimator 8 upon the slide 6 of the leveling rod 5; which latter is planted in such manner that the steel tape 9 shall be stretched but without acting upon the dynamometer spring.

The operator who is stationed at the ob servation vpoint then connects together by the means of the screw 59 and arm 5S the rulers 22 and 24 which have been made parallel, and then sights upon the slide 6; the ruler 24 is clamped by means of the tongue 3T against the edge 38, the adjustment being completed by the use of the screw he then releases the ruler 22 and sights the point B, operating in the same manner, after wli'ch he pushes the slide 46 until the edge of the block 48 enters into contact with the ruler 24; at this time by pressing upon the stud 5l he causes the pointer 52 on the plunger 50 to make a d ot on the paper at the desired point.

in order to lay7 out the` desired plan the cover of the circular scale 35 is preferably put in place. @n the contrary, in operations for the numerical determination of the position of the point B, the said cover must be removed in order to disclose the graduated scale portion, and in this event a large circular hole must be. made in the paper or oil cloth stretched upon the board.

As in the preceding case, when the perpendicular line has been marked out by the assistants, the operator sights the slide 6, clamps the ruler 24, sights the pointB, and pushes the slide 46 so as to bring the block 48 into contact with the ruler 24; he then takes the reading at the. vernier, and by a simple calculation he is enabled to determine the distance of the observed point in an accurate manner.

By looking through the glasses 57 and 34 he can also lind the angle between the rulers with great facility and hence, as may be readily conceived, the angle between the sighting line on the point B and a line represent-ing a stated direction which has been preliminarilymarked out.

The altitude of the point B can also be forint by observing the dierence of level between this point and the observation point; for this purpose the operator adjusts the sight glass in such manner as to render it horizontal; he then sights upon the point B by pivoting theV glass by means of the Y pinion 29, and then reads the corresponding` division of the vertical scale 53. This will indicate the. value of a quantity which is proportional to the difference of level sought for. Since this proportion can obviously be found according to the preceding operations, the difference of level will be therefore determined.

Fig. 7 shows a devi-ce whereby the edge of of the block 48 may be brought against the ruler 24 with the. saine pressure at all times. For this purpose, the effects of friction to be overcome in order to displace the slide 46 must be substantially constant. One side of the said slide is provided with a spring 77 attached to the rollers 7S which are thus maintained in contact with the ruler 22, se that friction will only occur on the other Side.

The said block is displaced by means of a button 7 9 mounted upon a rod 80 which is provided with a plunger 8l that bears against the adjacent end of a spring 82 disicev posed in longitudinal recess 83 in the slide; the other end of the spring bearing against the inner end wall of the recess, so that the inward movement of rod and its plunger will thus be transmitted through the spring to the aforesaid end wall of the recess and will act to shift the slide in the same direction. lt is to be observed, however, that the spring must be compressed to some extent before it will transmit sufficient pressure to move the slide;A and in the construction illustrated, the plunger 8l is equipped-with a projects into a short longitudinal guide slot 85 formed in the top of the slide which opens into recess 83, the movement of the slide commencing when said pin reaches a mark S6 located on the upper surface of the slide. and intersecting such slot.

0bviously, the arrangements hereinbefore set forth are susceptible of detail modifications without departing from the spirit of the invention, and in particular the means indicated for completing the adjustment for setting the ruler are given solely by way of example, and the same applies to the means for setting the rulers upon the instrument board.

pinv or pointer 84 which i lll) I claiin:

l. In a distance i'inder. the combination of a base plate; a pair ot coacting rulers mounted thereon to pivot about a cennnon axis in variable angular relation, one ruler being graduated; clamping ineans individual to the rulers tor independently securing theni to the base plate; nieans 'tor releasably connecting the rulers tegetlu-fr; a telescope carried by the graduated ruler to sight :don the saine towards a distant point; a slide carried by said gaduated ruler to contact with the adjace t Ytace oi the other ruler: a graduated vertical scale carried by the slide in the line ot sight ot the telescope to indicate the altitude ot' said peint; and an annular graduated scale on said base plate concentric with the connnon pivotal axis ot the two rulers to indicate thei angular relation.

2. In a distance iinder; the combination ot a base plate; a pair of coacting rulers mounted thereon to pivot about a coinn'ion axis in 'ariable angular relation` one ruler being graduated; clamping nieans individual to the rulers tor independently securing thein to the base plate; ineans 'tor rideasably connecting the rulers togethtuf; a telescope carried by the graduated ruler to sight along the sanie towards a distant point; a slide carried b v said graduated ruler provided with a block having an edge of predeterniined length which is perpendicular to one 'tace ot' the ruler and which is adapted to abut against the adjacent tace ot the other ruler: a graduated vertical scale carried by the -slide in the line ot sight ot the telescope to indi ,ite the altitude ot said point; and an annular graduated scale on said base plate concentric with the connnon pivotal axis et the two rulers to indicate their angular relation.

distance finder, according to claiin Q, in which the base plate is adapted to support a plotting sheet; and in which a hand-operated plunger is niounted on the slide at the apex ol the right-angle torino-d by the perpendicular edge o't' the block and the adjacent face of the ruler which carries said slide, said plunger having a pointer `riounted on it to malte a niark on the plotting sheet when the plunger is depressed.

fl. In a distance finder, the combination ot a base. plate; a pair of coacting rulers mounted thereon to pivot about a connnon axis in variable angular relation, one ruler being graduated; a clamping tongue pivotally connected to each ruler to engage the edge ot' the base plate and thereby hold the ruler in adjusted position; an operating screw tor each tongue; means t'or releasably connecting the rulers together; a telescope carried by the graduated ruler to sight along the saine towards a distant point; a slide carried by said graduated ruler to contact with the adjacent 'la 'ce ot' .the other ruler: a graduated vertical scale carried by the slide in the line t sighty ot the teleseope to indicate the altitude ot said point; and an annular graduated scale on said base plate concentric with the connnon pivotal axis ot the two rulers to indicate their angular relation.

In a distance linder, the combination oi a base plate; a pair ot coacting rulers mount- Vd thereon to pivot about a coninion axis in variable angular relation7 one ruler being graduated; clamping means individual to the rulers for independently securing tlieni to the base plate; nieans tor releasably connecting the rulers together; a telescope carried by the graduated ruler to sight along the saine towards a distant point; a slide carried by said graduated ruler to contact with the adjacent 'tace ot the other ruler and bearing a tixed indicating niark; and a spring-loaded eleinent t'or displacing said slide niounted on the slide and provided with a pointer Ytor cooperation with said niark.

t?. In a distance finder, the combination ot a 'oase plate; a pair ot' coat-ting rulers mounted thereon to pivot about a couuuon axis in varia-ble angular relation; one ruler being graduated: clamping ineans individual to the rulers tor independently securing thein to the base plate; a telescope carried b v the graduated ruler to sight along the saine towards a distant point; a slide carried by said graduated ruler provided w'th a block having an edge oi predetermined length which is perpendicular to one 'tace of the ruler and which is adapted to abut against the adjacent tace ot the other ruler; and an annular graduated scale on said base plate concentric with the connnon pivotal axis ot the two rulers to indicate their angular relation.

In testimony whereof I atiix niy signature.

ANDR FRANCOIS NECTGIX,

lUU 

